Tom Brady's father revealed an underlying truth about Brady's retirement decision, per Boston.com's Conor Roche.

“This has been a really rough six months on his personal life, his family life, and on his football life,” Brady Sr. said. “He once said this, he said, ‘I’m getting tired of getting hit.’ Having played 23 years and he holds the ignominious record of most sacks against in the NFL … and there must be another two or three thousand knockdowns.”

Tom Brady has been taking hits for 23 years. And that doesn't even include his high school and college days. He has displayed no shortage of toughness during his time in the league. But there's only so much one person can handle. Nobody would have blamed him had he retired 5 years ago. But the fact that he played through his age 45 season is remarkable.

Brady will go down as the greatest QB of all time. He's a future first-ballot Hall of Famer without question. With that being said, there are some people around the NFL world who were left feeling less than impressed by his career, such as Trent Dilfer.

“The modern-day game does not impress me,” Dilfer explained. “It’s super easy when you don’t get hit as a quarterback and when you can’t reroute receivers and when you can’t hit guys across the middle. I love Tom Brady. I love Aaron Rodgers. I love these guys. It’s not impressive. What’s impressive is what they (old school quarterbacks) did.”

Nevertheless, Tom Brady is generally regarded as the best QB to ever play the game.